Rule & Definitions

The following IRC Rule changes were approved by Congress in October 2017:

• In Rule 21.5 the ‘default’ values for mainsail widths have been deleted as this was inconsistent with the Rule on headsails.• The Dayboat Definition and Rule 24 have been deleted, as IRC cannot and should not judge OSR compliance.• The final sentence of Rule 8.2.1 has been corrected to reflect the intention of the Rule on short-handed certificates.• Rule 13.2 has been changed in accordance with IRC Notice 2017-01, relating to sail measurement batten length.• Rule 17.1 now clarifies that cushions are only relevant to measurement condition if carried while racing.• Rules 21.2.1 (Rig Factor) and 22.2.1 (Hull Factor) have been updated to reflect actual practice.• Definitions have been added for the measurement of lifting foils, to reflect the increased use of these and development of how they are rated.• Other changes are: deletion of the IRC Headsail Head Point definition as this is now identically defined in ERS; a correction to the Advertising Code reference in Rule 26.1; and confirmation that in Southern Hemisphere countries the new IRC Rule does not come into force until June 2018 (the exception is Rule 13.2 as Notice 2017-01 applied with immediate effect from May 2017).

IRC Rule changes 2016 – a summary• Rule 8.1 now includes a minimum LH of 5.00m to be eligible for an IRC rating (excepting boats previously rated)• Bulb Weight will now be recorded on a boat’s certificate where applicable, and Bulb Weight has been added to Rule 8.10.1 and the definitions.• Abbreviations for some sail measurements (LLmax, LL, LP, SF) have been updated but the definitions are unchanged.• The rule about setting multiple headsails simultaneously has been simplified, and new cutter rig definitions added.• IRC notice 2014/01 relating to reefing of spinnakers is now included as part of the spinnaker definition.• The definition of a Dayboat now includes an upper LH limit of 10.00m.• Rule 21.1.6 is extended to include moving the mast at foot or deck level for Dayboats.• Rule 9.8 rating review limits are amended in respect of weights.• A number of detail changes have been made throughout the text to correct typographical errors and inconsistencies in terminology, and the definitions have been re-ordered in categories for clarity.